Surface emitting laser-based device for light detection and ranging

Abstract

A device is described that includes a lens, a photonic substrate, and a surface emitting laser mounted and a set of photodetectors mounted on the photonic substrate. The photonic substrate includes a first surface coupler, a second surface coupler, and an interference coupler. The surface emitting laser emits electromagnetic radiation that is modulated according to a continuous wave frequency modulation. The first surface coupler directs a local oscillator portion of the electromagnetic radiation toward the set of photodetectors. The second surface coupler directs, toward the set of photodetectors, a signal portion of the electromagnetic radiation that is reflected from a target and received via the lens. The interference coupler optically interferes the local oscillator portion from the first surface coupler with the signal portion from the second surface coupler to generate a set of optical outputs that are provided to the set of photodetectors.

1 . A device, comprising:
 a lens;   a photonic substrate comprising a first surface coupler, a second surface coupler, and an interference coupler;   a surface emitting laser mounted on the photonic substrate, the surface emitting laser to emit electromagnetic radiation that is modulated according to a continuous wave frequency modulation; and   a set of photodetectors, wherein:
 the first surface coupler directs a local oscillator portion of the electromagnetic radiation toward the set of photodetectors; 
 the second surface coupler directs, toward the set of photodetectors, a signal portion of the electromagnetic radiation that is reflected from a target and received via the lens; and 
 the interference coupler optically interferes the local oscillator portion of the electromagnetic radiation from the first surface coupler with the signal portion of the electromagnetic radiation from the second surface coupler to generate a set of optical outputs that are provided to the set of photodetectors. 
   
     
     
         2 . The device of  claim 1 , wherein the second surface coupler further directs the electromagnetic radiation from the surface emitting laser away from the device via the lens for reflection from the target. 
     
     
         3 . The device of  claim 1 , wherein the first surface coupler further directs the electromagnetic radiation from the surface emitting laser away from the device via the lens for reflection from the target. 
     
     
         4 . The device of  claim 1 , wherein the surface emitting laser is configured to emit the electromagnetic radiation toward the first surface coupler of the photonic substrate and away from the device via the lens for reflection from the target. 
     
     
         5 . The device of  claim 1 , further comprising:
 a dual polarization meta optic element; and   a quarter-wave plate, wherein the signal portion of the electromagnetic radiation that is reflected from the target is sequentially received at the second surface coupler via the lens, the dual polarization meta optic element, and the quarter-wave plate, and wherein the electromagnetic radiation is emitted from the surface emitting laser away from the device for reflection from the target sequentially via the quarter-wave plate, the dual polarization meta optic element, and the lens.   
     
     
         6 . The device of  claim 1 , wherein at least one of the first surface coupler or the second surface coupler is a grating coupler. 
     
     
         7 . The device of  claim 1 , wherein at least one of the first surface coupler or the second surface coupler is a wedge coupler. 
     
     
         8 . The device of  claim 7 , wherein the photonic substrate further comprises at least one of:
 a first micro-lens disposed on the photonic substrate between the first surface coupler and the surface emitting laser; or   a second micro-lens disposed on the photonic substrate between the second surface coupler and at least one photodetector of the set of photodetectors.   
     
     
         9 . The device of  claim 1 , wherein the surface emitting laser comprises a single-emitting vertical cavity surface emitting laser, a dual-emitting vertical cavity surface emitting laser, a photonic crystal surface emitting laser, or a surface emitting distributed feedback laser. 
     
     
         10 . The device of  claim 1 , wherein the photonic substrate comprises:
 a silicon substrate layer;   a first one or more waveguides formed on the silicon substrate layer between the first surface coupler and the interference coupler, wherein the first one or more waveguides comprise silicon waveguides or silicon nitride waveguides; and   a second one or more waveguides formed one the silicon substrate layer between the second surface coupler and the interference coupler, wherein the second one or more waveguides comprise silicon waveguides or silicon nitride waveguides.   
     
     
         11 . The device of  claim 1 , wherein the photonic substrate comprises:
 a printed circuit board;   a first one or more polymer waveguides formed in the printed circuit board between the first surface coupler and the interference coupler; and   a second one or more polymer waveguides formed in the printed circuit board between the second surface coupler and the interference coupler.   
     
     
         12 . A device, comprising:
 a photonic substrate including a plurality of couplers;   a plurality of photodetectors mounted on the photonic substrate;   a plurality of surface emitting lasers mounted to the photonic substrate to emit electromagnetic radiation that is modulated according to a continuous wave frequency modulation; and   a lens coupled to the photonic substrate and configured to direct a signal portion of the electromagnetic radiation reflected from a target toward the photonic substrate,   wherein the photonic substrate is configured, for each surface emitting laser of the plurality of surface emitting lasers, to,
 direct, via a first surface coupler of the plurality of couplers, a local oscillator portion of the electromagnetic radiation from the surface emitting laser toward a set of photodetectors of the plurality of photodetectors; 
 direct, via a second surface coupler of the plurality of couplers, the signal portion of the electromagnetic radiation toward the set of photodetectors; and 
 optically interfere, at an interference coupler of the plurality of couplers, the local oscillator portion of the electromagnetic radiation with the signal portion of the electromagnetic radiation to generate a set of optical outputs that are received at the set of photodetectors. 
   
     
     
         13 . The device of  claim 12 , wherein the second surface coupler further directs the signal portion of the electromagnetic radiation from the surface emitting laser away from the device via the lens for reflection from the target. 
     
     
         14 . The device of  claim 12 , wherein the first surface coupler further directs the signal portion of the electromagnetic radiation from the surface emitting laser away from the device via the lens for reflection from the target. 
     
     
         15 . The device of  claim 12 , wherein each surface emitting laser of the plurality of surface emitting lasers is configured to emit the local oscillator portion of the electromagnetic radiation toward the first surface coupler of the photonic substrate, and emit the signal portion of the electromagnetic radiation away from the device via the lens for reflection from the target. 
     
     
         16 - 20 . (canceled) 
     
     
         21 . A device, comprising:
 a photonic substrate comprising a first surface coupler, a second surface coupler, and an interference coupler;   a surface emitting laser mounted on the photonic substrate, the surface emitting laser is configured to emit polarized light having a first polarization; and   a set of photodetectors, wherein:
 the surface emitting laser is positioned to emit the polarized light toward the photonic substrate; 
 the first surface coupler is positioned to capture a first portion of the polarized light as local oscillator light and pass a second portion of the polarized light that exits the photonic substrate as emitted signal light; 
 the second surface coupler is positioned to receive reflected signal light that is reflected and capture a portion of the reflected signal light having a second polarization as collected signal light; 
 the interference coupler optically interferes the local oscillator light with the collected signal light to generate a set of optical outputs; and 
 the set of photodetectors measures the set of optical outputs. 
   
     
     
         22 . The device of  claim 21 , wherein:
 the photonic substrate comprises a first waveguide layer and a second waveguide layer;   the first surface coupler is formed in the first waveguide layer; and   the second surface coupler is formed in the second waveguide layer.   
     
     
         23 . The device of  claim 22 , wherein:
 the first waveguide layer and the second waveguide layer are formed from different materials.   
     
     
         24 . The device of  claim 21 , wherein:
 The first surface coupler is positioned between the second surface coupler and the surface emitting laser.   
     
     
         25 . The device of  claim 21 , wherein:
 the photonic substrate comprises a polarization rotator configured to convert the local oscillator light from the first polarization to the second polarization.